Writing devices are used to record data handled by information processor apparatuses such as a computers on recording media that may be taken out of the information processor apparatuses. For example, recording media with data written thereon are saved and kept as backups of the data. An electromagnetic tape medium or an optical disk medium and the like may be used as the recording media. The recording media may be accommodated inside cases called cartridges for convenient handling.
However, writing data on a recording medium may fail due to an abnormality and the like in the writing device. Thus, methods to allow the continuation of data writing even when a writing failure occurs have been considered.
For example, there is a proposal that includes providing a backup memory in an optical disk medium, storing write data on the disk medium also into the backup memory so that the data may be recovered from the backup memory when a data writing error occurs.
For example, there is another proposal that includes a method called dynamic device reconfiguration (DDR) for writing data on an electromagnetic tape medium. When an error occurs in an electromagnetic tape device while data is being written on the electromagnetic tape device, the electromagnetic tape device reports the error to a host device. The host device saves unwritten data that has been backed up at the electromagnetic tape device side to a main memory in the host device. The host device instructs an operator to move the electromagnetic tape medium to another normal electromagnetic tape device. The operator moves the electromagnetic tape medium to the other normal electromagnetic tape device. The host device then uses the other electromagnetic tape device to add the saved unwritten data on the electromagnetic tape medium. In this way, data writing on an electromagnetic tape medium continues even if an error occurs in DDR.
There is a proposal in which a non-volatile memory is provided in a cartridge containing an electromagnetic tape medium, and partition information of the electromagnetic tape medium and user information and the like is stored in the non-volatile memory. There is also a proposal in which a non-volatile memory unit is provided in an electromagnetic tape medium cartridge and data written in the memory unit is rewritten to a position specified on the electromagnetic tape medium.
Japanese Patent Laid-open No. 6-175793, Japanese Patent Laid-open No. 2003-263840, Japanese Patent Laid-open No. 6-175792, Japanese Patent Laid-open No. 9-161452, and Japanese Laid-open Patent 2011-146105 are examples of related art.
When unwritten data is saved to a host device as in DDR, the size of the storage area for saving may be small in comparison to the size of the data to be saved. In this case, the data writing may be interrupted without being able to save all of the unwritten data. Thus, increasing the size of the storage area for saving in the host device may be considered. However, it may be difficult to properly secure a storage area for saving on the host device side when the host device is operating or when storage areas are assigned from the main storage device to other devices.
Accordingly, providing a memory in an electromagnetic tape medium cartridge to allow the use of a storage area in the memory for saving may be considered. However, in this case, incorporating a procedure for saving and writing data using a memory in a cartridge may lead to problems in suppressing costs with respect to existing DDR procedures in the host device.
For example, in a host device DDR procedure, remaking an unwritten data saving destination to use as a memory in a cartridge instead of a main storage device on the host device side incurs man-hours for conducting the remaking. Moreover, changing an existing procedure on a host device that is operating in a stable manner may also lead to the problem of incurring man-hours for careful preparation and actual work when considering the effect on other existing operating procedures.
An aspect of the embodiments discussed herein is to provide a writing system, a writing device, and a writing method that allow for the expansion of storage areas for saving data at a low cost.